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Every Inkbox inbox speaks IMAP and SMTP, so you can open it in a standard desktop or mobile mail app. It is the same inbox your agent uses through the API: mail the agent sends appears in Sent, a message you read in the client is marked read for the agent, and a thread the agent archives moves to Archive in your client.

Connection settings

Most people need nothing beyond this table. The username is the same for incoming and outgoing mail, and so is the password.

Getting the password

There is no separate app password. The password is an API key scoped to the agent identity that owns the inbox — mint one from the Console, or with an admin key, and paste it into your mail client as the account password. Two things to know:
  • An admin-scoped key does not work here. The key has to be scoped to an identity, because the login has to resolve to exactly one inbox.
  • One key opens exactly one inbox — the inbox belonging to the identity it’s scoped to. To connect a second agent’s inbox, mint a second key.
Revoking the key — or deleting the identity or its inbox — blocks new logins immediately. A session that is already connected is revalidated periodically rather than severed on the spot (SMTP re-checks before it accepts a message; IMAP re-checks as commands come in), so treat revocation as “no new access,” not as an instant disconnect.

Sending (SMTP)

From must be the inbox you signed in as

The most common setup failureThe From header of every message you send must contain exactly one address, and it must be the inbox address you authenticated as. If your client also sets a Sender header, that has to match too. Aliases and “send as” identities are rejected.If mail sends fine from the API but your mail client’s first outgoing message bounces straight back, this is almost always why: open the account’s identity settings and make sure the From address is the inbox address itself, character for character.

Leave “save a copy of sent messages” on

You don’t have to turn it off. Inkbox stores every outgoing message in Sent as it goes out. When your client uploads its own copy with the same Message-ID header, Inkbox recognizes it as the same message and points the client at the one already there. You get one entry in Sent, and it counts against your storage once. If a client omits or changes Message-ID, its uploaded copy appears as a separate entry and uses additional storage.

Limits and rejections

SMTP submissions run through the same path as API sends, so the same limits and quotas apply:
  • Up to 50 recipients and 10 MB per message.
  • A message rejected for policy reasons comes back as a permanent failure (550). A temporary failure (451) means try again shortly; most clients do that on their own.
  • If storing an outgoing message would push the inbox above its storage limit, the send is refused (552) until you free space by deleting messages. Receiving is never blocked. See pricing for the per-plan caps.
Idle connections are closed after 30 minutes; mail clients reconnect on their own.

Folders

The folder set is fixed. You cannot create, rename, or delete folders. Moving a message between INBOX, Archive, and Spam in your client is the same action as changing its thread’s folder through the API or the Console.

Archive and Spam move the whole thread

Inkbox files conversations, not individual messages. Moving one message to Archive or Spam moves its entire thread, so the other messages in that conversation leave your inbox along with it — and disappear from your client’s INBOX view. This is the same thing as changing the thread’s folder through the API. Trash is the exception: it is per-message. Moving one message to Trash deletes that message and nothing else. Changes you make in the client take effect right away. Changes made through the API, the SDK, or the Console appear in your client shortly after, on its next update.

Drafts sync across surfaces

Your mail app, the Inkbox Console, and the drafts API share one Drafts folder. An edit from another surface may appear as the old draft being removed and a replacement draft arriving. This is expected; refresh before editing if the draft changed elsewhere. Mail apps save a draft separately from sending it. After SMTP reports success, the app removes its own saved draft. Inkbox does not match an unrelated SMTP send to a draft automatically. Mail apps can save drafts up to 10 MB. Final send preparation may require extra headroom, so a draft near that limit can be rejected when sent. A rejected send leaves the draft intact. See Email drafts for the complete cross-surface workflow.

Trash means deleted

Moving a message to Trash deletes it, and its storage is freed right then. It stays listed in the Trash folder until your client expunges it; expunging removes it from the mail-client Trash view (it frees nothing further — the space already came back). The reverse holds too: a message you delete through the API, the SDK, or the Console shows up in your mail client’s Trash folder.

Behavior notes

  • IDLE is supported, so your client is notified of new mail without you refreshing it. Arrivals typically surface within about a minute.
  • Changes sync both ways. Read and flagged states, archives, and deletes made through the API, the SDK, or the Console appear in the client, and vice versa.
  • Drafts sync across surfaces. Mail-app, Console, and API drafts share the Drafts folder. Sending happens over SMTP in a mail app, and the app removes its saved draft after success.
  • COPY is not supported — the server tells the client to use MOVE instead. Mail clients move between folders by default, so this rarely comes up.

Custom email signatures

Your mailbox’s enabled custom signature also applies to mail sent over SMTP when the feature is available. Turn off the mail app’s own automatic signature if it contains the same content; Inkbox does not remove signatures your app already added. Saved drafts receive the current signature when sent, not while you edit them. Signed or encrypted message bodies cannot be sent while automatic signature insertion applies. Disable the mailbox signature and remove the branding footer to send them unchanged.
  • Outbound mail carries a short “Sent via Inkbox” footer by default, appended to the text and HTML bodies. This applies to mail sent from a mail client and mail sent through the API. Paid plans can remove it — see Branding footer.
  • Signed and encrypted mail can’t be sent from a mail client while the footer applies. S/MIME and PGP signing or encryption is rejected, because the footer cannot be added without invalidating the signature. Send unsigned, or remove the footer on a paid plan and disable automatic custom signature insertion.

Add the account manually

Autodiscovery won’t find these settings, so pick your client’s manual option:
  1. Add a new account and choose the manual setup path — usually called Other Mail Account, Manual configuration, or IMAP.
  2. Email address / username: the full inbox address, e.g. scout@inkboxmail.com.
  3. Password: the identity-scoped API key.
  4. Incoming mail (IMAP): host imap.inkboxmail.com, port 993, SSL/TLS, password authentication.
  5. Outgoing mail (SMTP): host smtp.inkboxmail.com, port 465 with SSL/TLS (or 587 with STARTTLS). Authentication required, using the same username and password.
  6. Save. The client syncs INBOX and shows the folder set above.
Before you send your first message, check the account’s From address — see the From rule.

FAQs

Yes — add one account per inbox, each with its own identity-scoped API key. A single key only ever opens the inbox belonging to the identity it’s scoped to.
Not when the uploaded copy preserves the original Message-ID header. Inkbox then matches it to the message already in Sent, so you can leave “save a copy of sent messages” enabled. If your client omits or changes that header, the copy appears as a separate entry.
Check the From address configured on the mail-client account. It must be the inbox address you authenticated as, and nothing else — no alias, no display-only “send as” address. See the From rule.
Yes. Moving a message to Trash deletes it and frees its storage immediately, whether or not your client has expunged the folder yet.